In the past, conventional off-the shelf toggle latches have been riveted or spot welded to an appropriate channel-sectioned band and used to secure the lids to the rims of the storage drums.
One disadvantage of using these conventional toggle latches is that their design and method of construction results in the pivoting points of the latch being spaced away from the connecting points of the latch which causes them to be bulky and to protrude significantly beyond the peripheral edge of the band. Such protuberances can cause damage to the storage drums during transportation and in some cases complicate the handling procedures.
A further major disadvantage resulting from the pivoting points of the latch being offset from the band, is that it is through these pivots that the closing force acts. Accordingly, it is not possible to properly tension the band against the drum at the point the latch overlaps the closure band. This can result in leakage from the drum at this point.
Another disadvantage is that the conventional toggle latches available are generally very difficult to attach to the closure band as the devices need to be manipulated into part-opened positions for welding or riveting.
When drums of this nature are used for the transport of dangerous goods, Commonwealth regulations require that the latches be secured so they cannot open during transportation. With many of the latches currently in use, this is achieved by tying down the toggle lever with wire passed through various apertures provided in the latch. Not only is the effectiveness of such methods in doubt, it can be a difficult, time consuming and expensive operation.
A further disadvantage with the conventional band to overlap during tightening of the latch. This additional operation increases the overall manufacturing cost of the assembly.
It is an object of the present invention to provide a toggle latch which will avoid or at least ameliorate the above disadvantages of the prior art.